Knockdown scaffold having safety lock



1954 c. F. MARONEY ETAL KNOCKDOWN SCAFFOLD HAVING SAFETY LOCK FiledSept. 13, 1951 IN VEN TORJ Patented Jan. 12, 1954 2,665,953 KNOCKDOWNsoAr'lgc r n HAVING SAFETY Clair F. Maroney, Daniel I. Weisz, and RalphW. McGrew, Ellwood City, Pa., assignors to Beaver Art Metal Corporation,Ellwood City, Pa., a corporation of Pennsylvania Application September13, 1951, Serial No. 246,366

2 Claims. (Cl. 304-40) This invention relates generally to knockdownscaffold and, in particular, to an improvement of the connector forsecuring diagonal braces or stays to the spaced rectangular end framesof such scaffolds in order to form a rigid self-sustaining structure.

Knockdown scaffolds are used extensively but as made prior to thisinvention they were not quickly and easily assembled but requiredconsiderable time and labor as well as the use of tools for erection anddismantling.

It is the object of this invention to provide a positive locking devicefor use with a scaffold.

In a preferred embodiment of the present invention, there are providedgusset plates at the junction of the horizontal and vertical members ofthe end frames. These plates are provided with keyhole slots extendingthereinto from an exposed edge, adapted to receive the end of a brace ora stay. There is also provided a brace with a head at each end and aflange spaced inwardly thereof. Between each head and flange there isrotatably mounted a collar having a segmental fiange and a handle forturning it. The segmental flange is adapted to enter the restrictedouter neck of the keyhole slot when turned to the proper position and tolock the brace in the gusset plate when the segmental flange is turnedperpendicular to the position for entering the keyhole slot. A lockingmember is slidably mounted in the segmental flange handle so as to beslidable transversely to its plane of rotation. In the locked positionthe locking member lies beneath the gusset plate so as to be adjacentthe lower edge thereof and prevent the rotation of the handle to theunlocked position.

A more complete understanding of the inven tion may be obtained from thefollowing detailed description and the drawings in which:

Figure 1 is a partial elevation of one end of a scaffold frame.

Figure 2 is a section through a horizontal member of one frame showingthe ends of braces secured thereto.

Figure 3 is a section through a horizontal member of a different frameembodiment showing the ends of braces secured thereto.

Figure 4 is a section of the horizontal member and gusset plate ofFigure 2.

Figure 5 is a section on the line 5-5 of Figure 4.

Figure 6 is a front elevation of the locking collar.

Figure 7 is a side elevation thereof.

Figure 8 is a side elevation of a segment of 2 brace member showinglocking collar in place thereon.

Figure 9 is a top plan View of the locking member of the invention.

Figure 10 is a side elevation thereof.

Referring to the drawings there are illustrated end frames i0 composedof posts l and beams l2 welded together. While both the posts I! andbeam I? are shown as fabricated from tubular members they may be made ofany other section or combination of sections. The end frames Ill of amultiple section scaffold are spaced apart and connected by braces orstays l3 extending from one end frame to another. The braces l3 areshown in the drawings as round bar stock but they may be of any otherdesired section. Gusset plates M are welded to the posts and beams inthe corners of the frames. Keyhole slots l5 are provided in the gussetplates, each having a restricted neck It adjacent an exposed edge of theplate and an eye I! spaced from the edge. The neck 5 is slightly greaterin width than the diameter of the braces l3. As shown in Figures 2 and 3there are gusset plates in each corner of the frame, which plates may beparallel to each other (Figure 2) or in the form of a V (Figure 3).

Each brace l3 has a head H3 in the form of a disc welded thereon orupset from the body of the brace. A flange I9 is welded at each end ofthe brace a short distance inwardly of the head I8. A collar 20 having amanipulating lever or handle 2| is rotatably mounted on the bracebetween each head l8 and flange I 9. The collar 20- has a segmentalportion 22 extending laterally thereof, which portions are of such widththat they will pass through the necks of the slots E6. The eyes ll ofthe slots have a diameter slightly greater than the outside diameter ofthe segmental portions 22 so as to permit rotation of the collars andsegmental portions after they have entered into the eyes of the slots.

The method of operation of these scaffolding members is believed to beapparent from the foregoing description; however, a brief description isas follows: The handles 2| are turned to the horizontal position (chainlines, Figure 5). This alines the segmental portions 22 with the necksof the slots I6 and permits them to pass therethrough. When the ends ofthe braces have thus been brought into the eyes of the slots, thehandles 2| are turned down to the vertical position. The braces are thuscentered in the eyes with the segmental portions 22 in such relation tothe necks l6 of the slots that they cannot be removed.

So long as the handles 2| remain in the vertical position, theassemblage above described constitutes a rigid, self-sustainingstructure. However, the handles 2| may he accidentally moved by beingbumped etc. to the horizontal position thus releasing the braces. Inorder to overcome this undesirable feature a locking member 23 isslidably mounted in a slot 24 in the handle 21 of the rotatable lockingcollar. One end 25 of the locking member is divided and the portions soformed turned outwardly from the body thereof in the form of wings orstops 26. 1 The other end 21 is notched to form a single projecting wing28 turned outwardly from the body thereof. These outwardly turned wings26'and 28 prevent the locking member from falling out of theslot 24. Thesingle wing 28 permits the use of two such looking members on adjacenthandles where the space is limited by reason of onebein'g able tooverlie th other in the manner shown in Figure 3. When the lockingmember is in the position shown in chain lines on Figure 4 the handle 2|can be freely moved to insert or release the braces. When the lockingmember is moved inwardly beneath the gusset plate (solid lines, Figure4) then the handle cannot be moved to the horizontal position since thelocking member strikes the bottom of the gusset plate preventingmovement of the handle.

While there has been illustrated and described but a single embodimentof this invention it will be understood that it may be otherwiseembodied within the scope of the following claims.

We claim:

1. In a separable connection for securing diagonal braces to therectangular end frames of a knockdown scafiold having at least onegusset plate on the end frame, each having a keyhole slot thereinincluding an eye and a restricted neck, a collar rotatably mounted oneach end of the braces, said collar having a portion shaped 4 anddimensioned to enter said neck when turned to one position and be heldagainst removal when turned to another position, retaining meansintegral with the brace on either side of the collar whereby the collaris maintained against axial or longitudinal movement, and handle meanson the collar for rotation thereof, the combination with said separableconnection of a pin mounted in an opening in the handle means formovement transverse to the plane of rotation of said collar wherebyrotation of said handle is prevented when said pin is in one extremeposition and freely rotatable when the pin is in the other extremepositiomsaid pin being slotted at one end and bent outwardly in oppositedirections from the plane of the body of the pin preventing removal fromthe opening in the handle at said end, the opposite end having a notchedportion and an outturned portion whereby the pin is removable at saidend by turning the pin into a plane parallel to the plane of rotation ofthe collar.

2. In a separable connection as claimed in claim 1 having a pair ofgusset plates in each corner of the frame and a pin slidably mounted inthe handle of each collar, said notched portion of one pin beingarranged to receive the outturned portion of the adjacent pin wherebyeach collar is locked against rotation.

CLAIR F. MARONEY. DANIEL I. WEISZ. RALPH W. MCGREW.

References Cited in the file of this patent UNITED STATES PATENTSNiunber Name Date 1,386,671 Zych Aug. 9, 1921 1,992,683 Webb et a1. Feb.26, 1935 2,483,862 Weisz Oct. 4, 1949

